The erosion of aluminum by solid particle impingement at normal incidence

A rotating arm apparatus was used to study the erosion of polycrystalline aluminum by 1.58 mm diameter WC-6% Co spheres impinging at normal incidence. Dynamic hardness values were obtained from measurements of the impact craters and compared with corresponding quasi-static values. In addition, material removal was monitored gravimetrically, and quantitative information was obtained on threshold and incubation phenomena and steady state erosion behavior. The variation of the velocity dependence of erosion with the number of particle impacts was derived from these data. Supporting scanning electron microscope studies suggest that the mechanism of material removal responsible for ductile erosion at near normal incidence is somewhat different from that which operates at shallower angles. The similarities and differences between these mechanisms are discussed, and it is suggested that together they account for the characteristic variation of ductile erosion with angle of impingement.